Health hazard evaluation report: HETA-2009-0025 and HETA-2009-0076-3085, evaluation of antimony and mercury exposure in fire fighters, Boca Raton Fire Rescue Services, Boca Raton, Florida, Tamarac Fire Rescue, Tamarac, Florida.
In October 2008, NIOSH received an HHE request from the Fire Chief at BRFRS in Boca Raton, Florida. The request concerned the possible exposure of BRFRS fire fighters to antimony through their station uniform pants made of FireWearŪ fabric. FireWear fabric contains antimony trioxide, which is often used for its flame retardant properties. In the weeks before the HHE request, 30 fire fighters had undergone hair testing for heavy metals after one fire fighter reported unexplained symptoms. All fire fighters were reported by the laboratory to have elevated antimony levels in their hair samples. As a result, BRFRS fire fighters ceased wearing the pants department-wide prior to submitting in early October 2008, and the HHE request was submitted. NIOSH investigators contacted the Acting Fire Chief at TFR in Tamarac, Florida to seek TFR participation in the HHE because its fire fighters were wearing uniform pants made from the FireWear fabric. In January 2009, NIOSH received an HHE request from the Acting TFR Fire Chief to evaluate antimony exposure in TFR fire fighters. We reviewed laboratory results for 30 BRFRS fire fighters who had submitted workers' compensation claims. Hair testing results for the 30 fire fighters, all from the same commercial laboratory, were reported as elevated. Twenty-three of these 30 fire fighters also underwent urine heavy metal testing by the same commercial laboratory. Only one fire fighter was found to have an elevated urine antimony level, but all 23 fire fighters had mercury levels that exceeded the testing laboratory's reference range. Though the laboratory reports stated that these were urine samples collected without any provocation, during our site visit some fire fighters verbally reported receiving a provoking agent prior to urine collection. During our on-site evaluation at BRFRS and TFR in February 2009, we met with fire executive staff and union representatives. We also administered questionnaires to participants that included personal characteristics, work history, and possible sources of exposure to antimony and mercury. We collected urine samples, which were analyzed for antimony and mercury by the National Center for Environmental Health at CDC. Twenty BRFRS fire fighters and 42 TFR fire fighters participated. All TFR participants had worn pants made from FireWear fabric while on duty in the preceding 2 weeks, and they reported wearing these pants for an average of 92 hours, or close to four 24-hour shifts, during this time. All BRFRS participants and all but one TFR participant were found to have urine antimony levels below or within the laboratory reference range for the general population. One TFR participant had a urine antimony level just above the upper limit of the laboratory reference range. Urine antimony levels of BRFRS and TFR participants were not significantly different. No BRFRS or TFR participant had a urine mercury level higher than the laboratory reference range. Urine mercury levels of BRFRS and TFR participants were not significantly different. Wearing pants made from FireWear fabric did not pose a health hazard from antimony exposure. Reliable and recommended testing methods with well-validated reference ranges should be used to measure the concentration of heavy metals in the body when health symptoms are consistent with overexposure to these metals. We recommend continued use of station uniforms that comply with the NFPA 1975 standard. Pants made from FireWear fabric are one product that meets this standard.